In recent years, flat panel displays have been utilized in various products and fields, and there are demands for flat panel displays having even larger sizes, even higher picture quality, and even lower power consumption.
In view of such circumstances, organic electroluminescent (referred to as EL below) display devices provided with organic EL elements utilizing the electroluminescence of organic materials are attracting a high degree of attention as flat panel displays, due to their excellent qualities, such as low voltage driving, high responsiveness, and self-luminosity, while being in a completely solid state.
For example, in an active-matrix organic EL display device, a thin film organic EL element is provided on a substrate, on which a thin film transistor (TFT) is provided. In the organic EL element, organic EL layers including a light emitting layer are layered between a pair of electrodes. One of the pair of electrodes is connected to the TFT. Then, image display is performed by applying a voltage between the pair of electrodes and causing the light emitting layer to emit light.
Further, in this kind of conventional organic EL display device described above, in order to prevent deterioration of the organic EL element caused by moisture or oxygen, a sealing film is known to be provided for the organic EL element.
In addition, in this kind of conventional organic EL display device described above, as disclosed in PTL 1 (see below), for example, it is proposed to provide, on the organic EL element, a gas barrier thin film layered body (sealing film) in which a stress relaxation film (an organic film) and an inorganic film are alternately layered. Then, in this conventional organic EL display device, it is said that deterioration of the organic EL element caused by moisture or oxygen can be inhibited by the sealing film.